Background

An eyelid coloboma is a full-thickness defect of the eyelid. Although an eyelid coloboma can occur in many locations, the most common position is at the junction of the medial and middle third of the upper lid. No lid appendages or accessory structures are usually seen within the coloboma.

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Pathophysiology

An eyelid coloboma may occur either congenitally or as a result of trauma (eg, accidental, surgical). An eyelid coloboma is an almost constant feature of Treacher Collins syndrome, which is autosomal dominant with variable penetrance and expressivity.

Upper eyelid coloboma is often associated with cryptophthalmos and, as a result, can occur in any genetic diseases involving cryptophthalmos, including Fraser syndrome (cryptophthalmos syndrome) and Manitoba Oculotrichoanal (MOTA) syndrome.
[1, 2]

A case review of upper eyelid coloboma with or without cryptophthalmos included 26 children (age range, 1 d after birth to 15 y).
[3] Of these 26 children, 19 had upper eyelid coloboma, 4 had classic cryptophthalmos, and 3 had both eyelid coloboma and cryptophthalmos. Of the 19 cases of upper eyelid coloboma, 5 occurred in isolation, 11 were associated with facial deformities, and 3 were part of a first arch syndrome (according to the Mustarde classification). All cases of classic cryptophthalmos were sporadic and nonsyndromic.

In this case review, Nouby concluded that upper eyelid coloboma with facial deformities and cryptophthalmos could be considered as one anomaly.
[3]